The invention relates to a heat engine for a motor vehicle.
The invention relates more particularly to a heat engine for a motor vehicle, of the type which comprises at least one cylinder block which comprises a first internal circuit for the circulation of a cooling liquid, of the type in which the first internal circuit comprises an internal supply duct an inlet orifice of which opens into a reception chamber or “volute”, that is substantially cylindrical, of a rotor belonging to a water pump of the engine, which is formed in the block, said chamber comprising in an intermediate portion a supply orifice the level of which is arranged above the level of the inlet orifice of the internal supply duct of the first internal circuit.
Many examples of heat engines of this type are known.
A known disadvantage of this type of engine is associated with the particular arrangement of the orifice for supplying the reception chamber or “volute” of the water pump with respect to the inlet orifice of the first circuit.
Specifically, in this configuration, when it is desired to fill the cooling circuit by gravity, an air pocket forms in the upper portion of the reception chamber or volute which is situated above the level of the orifice for supplying said reception chamber.
This residual air pocket prevents the priming of the water pump when the engine is started, which may result in damage to the water pump or a lack of the circulation of the cooling liquid within the cooling circuit of the vehicle.
It is therefore necessary to fill the cooling circuit under pressure in order to achieve a correct priming of the water pump.